How do trees survive the winter?

Trees - essential for civilization - can adopt two different strategies to handle the winter; deciduous shed their leaves in the autumn while evergreen retain them.

A main challenge for deciduous trees is to correctly time the onset of leaf senescence, to ensure that nutrient retrieval is optimized, while conifer needles need to have super-efficient systems to handle high light intensities at very low temperatures. We will study the molecular mechanisms behind these adaptations.

In one part of the project, we are for example use profiling of hormones, metabolites and transcripts in a systems biology approach to study regulation of autumn leaf senescence. We will also construct mutants to decipher key regulatory steps.

In the second part, we will elucidate additional aspects of the novel photosynthetic regulatory mechanism – direct energy transfer from photosystem II to photosystem 1 – that we have identified in the previous granting period, and that makes it possible for conifer needles to remain green throughout the winter.

We will try to connect the mechanism to specific proteins and pigment-protein complexes in the conifer needles. But we all also explore the role of the mechanism in angiosperms.